Is high-resolution anoscopy different from a colonoscopy?

A colonoscopy examines the whole large bowel, while a high-resolution anoscopy focuses only on the anal canal. High-resolution anoscopy can be used to look at very small changes that might not be visible during a colonoscopy. High-resolution anoscopy is a much quicker procedure and does not require the same preparation as a colonoscopy (a prescribed diet and a laxative before the procedure).